306 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



Head black, yellow as follows: Lateral lobes of the lower lip; base 

 of mandibles; a basal spot on either side of the upper lip; a spot at 

 either end of the nasiis; sometimes a trace at middle of rhinarimn 

 and middle of lower edge of nasus; the upper half of the frons in 

 front and all the frons above, excepting the extreme base; the 

 occipital plate at the middle, or entirely black. 



Prothorax black, yellow as follows: The anterior border, a geminate 

 median spot on the middle lobe, a small spot just behind it, and a 

 large spot on either side. Thorax above black, largely yellow 

 between the wings; middorsal carina with its extreme edge yellow 

 for a short distance; straight, slightly divergent, yellow dorsal stripes 

 of nearly uniform width throughout, almost reaching the antealar 

 smus above and connected below with the slightly narrower, broadly 

 interrupted, mesothoracic half collar; just behind the upper end of 

 the dorsal stripe is a round spot representing the antehumeral stripe; 

 in one specimen this spot is prolonged downward about two-thirds 

 the length of the mesepisternum by the faintest, frequently inter- 

 rupted line; in another case the spot is reduced to the merest pin point; 

 mesepimeron with a broad j^ellow stripe, represented on the mesin- 

 frgepisternum by an isolated spot; metepisternum with a narrow 

 irregular yellow stripe which is infringed on by the black stripes on 

 the 2 lateral sutures and which ma}^ be thereby completely obliterated 

 excepting, for a large inferior spot; metepimeron largely yellow, with 

 the black of the second lateral suture on its upper edge, and a slight 

 trace of black on its lower edge. Pectus dark, almost or quite black. 



Legs black, venation black, or dark brown; stigma reddish brown, 

 surrounded by black veins; membranule almost wanting; anal 

 triangle in male 3-celled. 



Abdomen slender, 7-9 moderately dilated for the genus; black, 

 yellow as follows: A dorsal longitudinal stripe on 1 and 2, trilobed on 

 2, in one specimen continued as the merest line to the apex of 3; sides 

 of 1 and 2 below largely j^ellow, auricles yellow, genitalia black; 3-7 

 each with a basal yellow ring, not quite reaching the lower edge of 

 each segment, narrowly interrupted in the middorsal line on 7, widest 

 on 3, where it occupies about one-fourth of the segment, on 4-6 

 occupying scarcely one-fifth, and on 7 about one-fifth of each seg- 

 ment; 8 has a transverse basal linear spot on either side (wanting in 

 one sjiecimen), representing the basal ring of the preceding segments, 

 and a small lateral apical spot, variable in size ; in one specimen 8 has 

 an inferior subbasal lateral spot equal in size to the more suj^eribr 

 lateral apical si:)ot ; 9 above with the apical half or three-fourths yellow, 

 the yellow area widening rapidly posteriorly, but not quite reaching 

 the extreme lower edge of the segment; in shape this yellow area is 

 that of a truncated triangle; 10 and appendages black; in one speci- 

 men 10 has a small round apical spot on either side of the dorsum 



